How to Build Stairs With Enclosed Risers

Install a 30-by-8-by-2 inch pine board, the joist, horizontally to the porch, centered where you will install the stairs, using 3-inch wood screws and a cordless drill. This is a four-step stair measuring 32 inches in height. The joist must be placed on the porch where the lengthwise center of the board is 28 inches above the ground.

Set a framing square on a 60-by-12-by-2 inch pine board so the corner, also called the heel, angles perpendicularly to one 60-inch edge of the board and the tongue, the thinner edge of the square, points toward or crosses over the 12-inch end of the board. The square will look like a V sitting on the board. The tongue will measure the rise of the stringer, 8 inches, and the body will measure the depth of the step, also called the run, 12 inches. With the heel perpendicular to the edge of the board, move the square until the tongue measures 8 inches from the heel to the end of the board. Set the gauges on the tongue and body so they firmly fit along the 60-inch edge of the board opposite the edge the heel touches.

Place the square on three 60-by-12-by-2 inch pine boards, called stringers, with the gauges on the body and tongue firmly along one 60-inch edge of the board and the corner of the square aligned with the opposite 60-inch edge of the board. Mark the outside of the square with a pencil on both, the tongue and body, where the tongue measures 8 inches from the end.

Move the square down the board so the rise measurement, 8 inches, measures from the line drawn on the body previously to the heel. Trace the outside of the square again. This process has just drawn two triangles on the board. These are the notches for the risers and treads of the stairs. Continue to draw the notches on the board until you have three full notches and one half notch at each end of the board.

Cut the notches and half notches out of the stringers using a circular saw.

Nail the stringers to the joist 9 inches apart with the middle stringer centered on the joist. Use 4-inch wood screws to attach the stringers to the joist from behind the joist.

Install a 9-by-1-by-1 inch pine board, called a cleat, between each pair of stringers, using 2-inch wood screws through the cleats into the joist and porch. Drill a 2-inch wood screw into the cleat ends through the stringers, using a cordless drill.

Install a cleat between the stringers at the bottom, 1/2-inch from the front of the stairs, using 2-inch wood screws and a cordless drill.

Center a 26-by-8-by-1 inch pine board, called a riser, to the lowest vertical section of the stringers, using 2-inch wood screws and a cordless drill. Install a riser to each of the four vertical sections of the stairs. There will be an inch of board hanging over each end of the riser.

Screw a 26-by-6-by-2 inch pine board, called the tread, to the horizontal section of the stringers, flush against the risers, using 3-inch wood screws and a cordless drill. Center the board so there is a 1-inch section hanging over each end of the stringer. Install a tread board to each horizontal section flush with the riser.

Screw a second tread board to each horizontal section of the stringers, 1/4-inch from the first, back tread board, using 3-inch wood screws and a cordless drill. These boards will have 1-inch overhang on each end and 1/2-inch overhang on the front of the steps, called the nose.

Sand all pieces of the stairs using sand paper and a sanding bar. Remove any chips, nicks, or splinters to prevent injuries.